Stroke is the third leading cause of death in the United States and afflicts over 700,000 Americans each year. Treatment of acute ischemic attacks focuses on early intervention to minimize the degree of tissue loss in the brain. Magnetic resonance imaging (MRI) using proton based diffusion and perfusion techniques, has become an essential clinical service for evaluating the degree of stroke pathology. The capabilities of MRI in stroke evaluation would be enhanced by including sodium imaging. Tissue sodium concentration measured by sodium MRI would complement diffusion and perfusion MRI data by rapidly and directly evaluating regional tissue viability. Such data allows the identification of the volume of tissue that may be salvageable to be balanced objectively against the risk of hemorrhagic complications of thrombolysis by reperfusing already non-viable tissue. The present Phase I SBIR application proposes to develop a dual-tuned sodium/proton radiofrequency head coil at 3.0 Tesla for use in clinical service. This technology will be developed in three steps: 1) multi- conductor transmission line and finite element methods will be used to numerical simulate and optimize the electrical circuit design; 2) industry-standard mechanical CAD programming will be used to generate a 3-dimensional model of the coil and circuit layout, and 3) the coil will be evaluated for SNR, sodium quantification, spatial resolution, B1 homogeneity and acquisition times acceptable for sodium and proton imaging at 3.0 Tesla. The development of a robust, sodium/proton dual-tuned, head coil would help with the management, image acquisition, and diagnosis of critically ill stoke patients. The proposed technology will be used with MRI in a clinical service to diagnose, treat and manage critically ill stroke patients. [unreadable] [unreadable] [unreadable]